Two dissident Chinese writers have been detained as police tried to block China's branch of an authors' group from holding an awards ceremony.

The move against the writers adds to a series of efforts by the communist government to tighten controls on civil liberties and stifle dissent ahead of the 2008 Beijing Olympics.

Li Jianhong, a Shanghai-based writer, was put under house arrest last week to block her from receiving an award at the Beijing ceremony organised by the Independent Chinese Pen Centre, said Liu Xiaobo, a political essayist and a former university professor.

Liao Yiwu, who was to receive the group's Freedom to Write Award, was detained when he arrived in Beijing, and police said that he would be sent back to his home in China's southwest, Liu said.>Associated Press